a hormone required by cells in order for them to remove and use glucose from the blood

Insulin is secreted by areas within the pancreas known as Islets of Langerhans. Although the level of insulin in the body is supposed to be fairly constant, such is not the case in people who suffer from diabetes, and those who have diabetes often have to get their insulin from shots.

microscopic view of Islands of Langerhans

location of the pancreas

Insulin was the first hormone ever identified, by Frederick Banting and Charles Best in the early 1920's. Banting and Best tied string around the pancreatic duct of several dogs; when the pancreases were examined later, all of the pancreas digestive cells were either dead or absorbed by the immune system, leaving only thousands of pancreatic islets behind. The men then isolated the protein from the islets and discovered insulin.

In 1922, Banting and Best perfected a method for extracting insulin from cattle and pig pancreases, and their method remains the most commonly used one today. However, some diabetics do not respond well to non-human insulin, and for these patients insulin that has been genetically reproduced (using a process approved by the FDA in 1982) is used.

SEE ALSO
Frederick Banting

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This page was last updated on 02/21/2017.